web application development landscape: technologies and models€¦ · università di pisa web...

Università di Pisa

Web application development landscape: technologies and models

Dipartimento di Informatica

by Andrea Nicchi

Relatore: Prof. Antonio CISTERNINO Controrelatore: Prof. Giuseppe ATTARDI

Università di PisaWeb application development landscape: technologies and models

“ an Information System providing facilities to acces s complex data and interactive services via the Web” [10.02]

WEB APPLICATION


[10.02] Gnaho, C. (2001), Web-Based Information Systems Development – A User C entered Engineering

Approach , Lecture Notes in Computer Science, Vol. 2016, pp. 105 – 118.;


Web Document;

HTTP Protocol;

Web Browser;

Web Server and Content Delivering;

AJAX and REST;

State Management: Session Control;

Web application development approaches;

Example: Shopping Cart.

TABLE OF CONTENTS



Formalisms used for representing a web document:WEB DOCUMENT


- GML: IBM 1969;- SGML: ANSI 1983;

- HTML 4.01 - 1999;- XHTML 1.0 (bridge to XML);

HTML provides a semantic description of the content and establishes a document structure (a hierarchy of elements)

- HTML 5 - 2007.


Defines: the way of exchange of the messages and th e format of the messages

HTTP PROTOCOL


Client/server structure, connection-oriented, stateless, no attempt is made to recover from failure;

HTTP uses the resource identification mechanism provided by Uniform Resource Identifier (URI)

Request-Response Message Paradigm;

HTTP MIME support content type.

( URI, URN );


BROWSER: reference architecture


[4.01] Alan Grosskurth, Michael W. Godfrey, Architecture and evolution of the modern web browse r, David R. Cheriton School of Computer Science, University of W aterloo, Waterloo, 2006;

Conceptual Mozilla FireFox Architecture;Concrete Microsoft Internet Explorer.


WEB SERVER: reference architecture


[5.11] Ahmed E. Hassan and Richard C. Holt Software Architecture Group (SWAG), A Reference Architecture for Web Servers , Dept. of Computer Science University of Waterloo, Ontario;


WEB SERVER


Processing Model (Process-based, Thread-based and H ybrid model)

Pool size behaviour (Static approach and Dynamic ap proach)

Conceptual architecture Apache Server 1.4;

COMMERCIAL WEB SERVER

Concrete architecture Microsoft IIS 7.0;


WEB SERVER CONTENT DELIVERING


Static Content

Dynamic Content

Simple HTMLAs-is page (header+content)

CGI: Common Gateway Interface

FastCGI: Fast Common Gateway InterfaceSSI: Server Side Include (.shtml)

PHP: PHP Hypertext Preprocessor /Personal Home PageJava ServletJSP: Java Server Pages (Java Beans, JSP 2.0 JSTL+EL )JSF: JavaServer Faces

ASP: Active Server Pages (ISAPI extension)

ASP .NET Web FormsASP .NET MVC (Front Controller + MVC Model 2)


retrieving content from the server to be inserted into the current page and transmitting new or update information to the server, without causing a total refresh or re-rendering of the current page.

AJAX

(Asynchronous Javascript And XML or Asynchronous Javascript And XMLHttpRequest)


AJAX WITH HTML HIDDEN FRAME (<frameset>);

AJAX WITH HTML INTERNAL FRAME (<iframe>);

XMLHttpRequest object.

DHTML (JavaScript, CSS and DOM ) + XMLHttpRequest (XHR)

What

By

How


A new approach to the web application design. “a coordinated set of architectural constraints that attempts to minimize latency and network communication while at the same time maximizing the independence and

scalability of component implementations” (Fielding 2000).

REST (REpresentational State Transfer )


1) data elements (resources, resource identifiers, representation);

2) connecting elements (client, server, cache, resolver, tunnel);

3) processing elements/components (user agents, origin server, intermediate comp.).

REST applied to HTTP1) nouns (URI);

2) verbs (actions: POST, GET, PUT,…);3) metadata (MIME-types,…);

4) contents (Content-type MIME type).

Architectural elements:


Web Application State Management


Session Control;

State Mngt Patterns;

Web Application Approaches;




Flow control problem

EP stands for Entry Page, AP(k)i stands for Application Page i of the Session k and FP stands for Final Page

User interacts:

browser;web page.




Session control problem

WAS(i): stands for Web Application State at the stage i;SR(j): stands for State

Representation j.

A web application session is a sequence of related user requests and web server responses, which are treated as a single interaction.


WEB APPLICATION: SESSION CONTROL


Client-side mechanisms (client’s web page or client’s local storage)

Server-side mechanisms

Cookies Hidden fields (visible with view source)

Application Object (multiple session vars, Lock, Unlock)

Session ObjectFile/Database

ViewState/Control State (“invisible” with view source – compressed and

encoded)

Query Strings




Session Control;




WEB APPLICATION STATE MNGT PATTERNS


Split context




Robust split context




Secure Robust split context




Session Control;




CGI Web Application



ASP/PHP/JSP Web Application



ASP.NET Web Form Web Application



ASP.NET MVC Web Application



JSF Web Application



CMS based Web Application


a set of built-in functionalities such as:

set of templates;

database connection;

API for session control, authentication, authorization etc.

integrated shopping cart management;

integrated search engine

CMS-based Web applications as a Web application for the management and control of content


Web Application Conceptual Architecture


The following architectural patterns describe the various type of Web Applications.


Web Application Conceptual Architecture


the technology changes but the architecture doesn’t change

Exec cics receive map

Exec cics send map


Shopping Cart Web Application


http://www.coronarie.it/shoc/Store.asp .

http://www.volucer.it/ShoCRP/RPStore.php

Paper Shopping Store




http://www.coronarie.it/shoc/Store.asp .




http://www.volucer.it/ShoCRP/RPStore.php


GRAZIE !!!PER L’ATTENZIONE


Web application development landscape: technologies and models

web application development landscape: technologies and models€¦ · università di pisa web...

Documents